1. Field of the Invention
The present invention generally relates to a light emission module and a light guide plate and a manufacturing method thereof. Particularly, the present invention relates to a light emission module and a light guide plate and a manufacturing method thereof that can reduce the loss of light energy.
2. Description of the Prior Art
The current backlit keyboard, from top to bottom, may include a set of keys, a mask, a light guide plate, a light source, and a reflector. The set of keys include multiple keycaps formed of light-transparent material. In general, the light source is composed of multiple light-emitting elements and the light-emitting diode (LED) is usually selected as the light source for the backlit keyboard. The light guide plate receives light emitted from the light source and the light is then emitted toward the set of keys by guidance and scattering of the light guide plate. In addition, the mask is disposed over the light guide plate and formed with light-penetrable portions corresponding to the keycaps. The light traveling within the light guide plate can be emitted out of the keycap through the corresponding light-penetrable portion, so that the symbol on the keycap can be identified.
Due to the limitation of soldering accuracy of the surface-mount-technology (SMT) equipment, the actual position of the light-emitting element soldered on the circuit board usually shifts from the preset position, so that the through hole of the light guide plate must have sufficient space for allowing the shifted light-emitting element to pass therethrough. As such, the gaps between each of the light-emitting elements and the light guide plate are different. Because of the exist of gap, a portion of light from the light-emitting element will transmit to non-light guide plate portions, such as the mask, resulting in the loss of light energy caused by the absorption and scattering of light. Therefore, the actual amount of light received by the light guide plate is less than what is expected. Moreover, due to the gaps of different sizes, the intensity of light to different directions from the light guide plate will be non-uniform.
For example, in the case of two rows of light sources disposed on the center of the keyboard to respectively emit lights toward the left side and the right side of the keyboard, when the gaps between the light sources that emit lights to the left half keyboard and the light guide plate are smaller and the gaps between the light sources that emit lights to the right half keyboard and the light guide plate are larger, the left half keyboard will be significantly brighter than the right half keyboard. Consequently, the brightness in the left half keyboard and the right half keyboard is non-uniform, impairing the viewing experience of the user.
Therefore, how to reduce the loss of light energy from the gap between the light source and the light guide plate to improve the lighting effect of the backlit keyboard is a challenging issue.